An example of a blow out grill in the background art for blowing out air in a vertical direction relative to an installing face is disclosed in Japanese Patent Unexamined Publication No. H10-325590.
However, in a blow out grill of a type which blows out air in the vertical direction relative to the installing face, air supplied from the blow out grill may directly impinge on a person in a room. Therefore, there is the problem that when supplied air is air from outside of a house in the winter, or simply cooler air in the summer, a blown out air flow constitutes a cold draft. On the other hand, although when air is blown out in a horizontal direction relative to the installing face an unpleasant feeling due to the cold draft (hereinafter, referred to as unpleasant feeling) can be prevented, there is the problem that the air flows along the installing face by the Coanda effect, and powder, dust, and the like, mixed in the air adheres to and contaminates the installing face.
Hence, there is disclosed an example of a blow out grill simultaneously resolving the two problems by using a plurality of sheets of fins in Japanese Patent Unexamined Publication No. H10-306933.
The blow out grill of the background art will be explained in reference to FIG. 6 as follows. As shown by FIG. 6, the blow out grill is constituted by panel base portion 101 having a room inner side opening and a room outer side opening to form a path for blowing carried air therebetween, panel portion 102 connected to panel base portion 101 and communicated with the blowing path, and a plurality of fins 103 provided at panel portion 102. Further, the respective fins 103 are installed such that imaginary extended lines thereof substantially constitute a radial shape. In this way, air supplied from the blow out grill can be diverged with a uniform wind speed and in a wide range, and therefore air can be blown out at a low wind speed. As a result, since a force of adhesion to the installing face is proportional to the wind speed, the installing face can be prevented from being contaminated by the Coanda effect. Further, since a very low wind speed is achieved in a vicinity of a person in a room, the unpleasant feeling can be alleviated.
However, in this case, there is the problem that the view in a room is deteriorated since powder and dust in the supplied air adheres to all of the fins. Further, even when the fins are cleaned, there is the problem that it is very difficult to clean the fins since the intervals between the fins are narrow. Further, there are the problems that the angle of the fins needs to be set accurately, and that the number of parts is increased by using a plurality of fins, and therefore the blow and grills become expensive.